I am going through the same thing with my husband and feeling the same emotions you are right now.
I moved here in September 2012 and my marriage is hanging on by a thread. We have a seven month old son who I have being raising alone the majority of the time. I found out so many things about my husband since I landed such as debts etc that he didn't tell me about all my trust for him has dissolved. His family are a nightmare and spend half their time attacking each other and his mother is just poisonous. His friends wont socialize with me because of the unkind rumours his mother has spread about me. His friends children have stolen my clothes and I have had a whole bunch of unpleasant medical issues to deal with and he has been nowhere to be seen. He has failed to support me emotionally and is packing me off to see a psychiatrist. Sorry to vent but it does help. I haven't even got the luxury of workplace friends as to them, my british accent is a novelty and when the customers abuse me because of it, no one backs me. Its all rather distressing.
Are you planning to remain in the US? If so, you are very brave and I admire you.
Have to tried to reach out to some of your colleagues at work? I know you feel they don't care but I have found one colleague I work with that although we don't socialize outside of work, she understands what I am going through with the immigration and homesickness. Are there clubs or social meet ups you and your daughter could do together? I think we are both outside of the main cities, so it's certainly hard to find these things. I am in a town where I am the only immigrant!
Texas' experience is common through all that I have been reading and when you have had lots of major life changes in one go, it is hard. Hang in there, you seem to be a strong person and very brave too. I thought I would let you know that you're not the only one having to go through this. I think there is a different side to simply moving over to live in a foreign land with a new husband or wife people don't think of and its just something that happens sometimes.